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Re: [TF-ENT] URIs for entailment regimes in service descriptions

From: Sandro Hawke <sandro@w3.org>
Date: Sun, 01 Nov 2009 12:47:02 -0500
To: Birte Glimm <birte.glimm@comlab.ox.ac.uk>
cc: SPARQL Working Group <public-rdf-dawg@w3.org>
Message-ID: <4756.1257097622@waldron>

> one of the problems with just saying OWL is that reasoners that use
> Direct semantics only work on a subset of RDF documents (those that
> fall into the OWL DL syntactic fragment). Most will not even parse
> non-OWL DL documents and OWL EL reasoners might not even parse OWL DL
> documents.

This is where "repair" comes in.  It's not standardized, but it doesn't
have to be.  My hope is that OWL DL reasoners will modify the graph to
something they can reason with, thereby becoming sound (but incomplete,
of course) RDF-Based-Semantics reasoners.  (They also have to do a few
tricks detailed in [1], I guess.)  If they do this, we'll have a whole
lot more interoperability.  

In particular, for the market, I believe it is crucial that users who
are not expert ontologists never have to pay attention to which profile
or semantics are being used for OWL.  I don't yet know the best way to
motivate implementors, though.

> Since these URLs are for the service descriptions, it is not the user
> that specifies this. 

Hmmm.  Isn't there also a proposal to allow SPARQL clients to ask/allow
the server to do reasoning, some way for clients to turn on/off the
reasoning in the server?  [ Sorry for not being up on the drafts yet ]

For service description, what profiles and semantics should be used to
describe a reasoner which does DL but can also handle some Full?  All
profiles, and both semantics?  To correctly handle the little cases
where the semantics differ even within the DL subset, the client's going
to have to say which one to use, I think.  (Or the service descriptions
will have to name different graphs within that endpoint, or some such
trick.)

   -- Sandro

[1] http://www.w3.org/TR/owl2-rdf-based-semantics/#Appendix:_Relationship_to_the_Direct_Semantics_.28Informative.29
Received on Sunday, 1 November 2009 17:47:15 GMT

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